Double action draw press



Sept. 4, 1962 R. F. DEHN ET AL 3,052,200

DOUBLE ACTION DRAW PRESS Filed Deo. 5, 1956 4 Sheets-Sheet l Sept. 4, 1962 R. F. Dl-:HN ET AL 3,052,200

DOUBLE AcTxoN DRAW PRESS Filed Deo. 5, 1956 4 Sheets-Sheet 2 INVENToRs oy fc.' @EH/v l i Afro@ Eys Sept. 4, 1962 R. F. DEHN ET AL 3,052,200

DOUBLE ACTION DRAW PRESS 4 Sheets-Sheet 3 Filed Dec. 5, 1956 BY WML/AM E WARD Arr-a Nays Sept. 4, 1962 R. F. DEHN ET AL DOUBLE ACTION DRAW PRESS 4 Sheets-Sheet 4 Filed Deo. 5, 1956 GNN 5 www, if V0 l@ W. 0 c/ wi/ l y r 0 on 3,052,200 DUUBLE ACTION DRAW PRESS Roy F. Dehn, Wicklie, and William E. Ward, Shaker Heights, Ohio, assignors to The Cleveland Crane & Engineering Company, Wickliife, Ohio, a corporation of Ohio Filed Dec. 5, 1956, Ser. No. 626,447 3 Claims. (Cl. 113-38) The present invention relates to draw presses and more particularly to a double action `draw press having a four point blank holder slide.

The principal object of the present invention is the provision of a new and improved press having a frame including spaced side plates, a blank holder slide reciprocable within the frame, a die slide reciprocable within and relative to the blank holder slide, and actuating means for reciprocating the slides, lthe press being so constructed and arranged that it forms a compact inachine having relatively simple operating linkages for the slides, particularly the blank holder slide, which linkages are readily assembled into a small space and provide relatively trouble-free operation `for long periods of time as well -as the necessary dwell in the oper-ation of the blank holder slide.

Another object of the present invention is the provision of a new and improved ldraw press having a frame including spaced upright side plates, a rectangular blank holder slide reciprocable between the side plates, linkages connected to the front and 4rear sides of the blank holder slide adjacent the corners thereof, and a horizontal crank shaft extending between the side plates for actuating the linkages, the linkages being lconnected to slide members supported by the side plates of the press and preferably reciprocated from a single eccentric means rotated by the crank shaft.

Another object of the present invention is the provision of a new and improved single point press having a frame including spaced vertical side plates and a four point blank holder slide disposed between the side plates and reciprocated by toggle linkages, the press being so constructed and arranged that the linkages are actuated by a crankshaft extending between the side plates and the knees of the toggle linkages break outwardly of the frame in a plane parallel to the side plates of the press.

The present invention resides in certain construction and combinations and arrangement of parts and further objects and advantages thereof will be apparent from the following `detailed description of the preferred embodiment made with reference to the accompanying drawings forrning a part of this specification and in which:

lFIG. 1 is a side elevational view, with parts cut away, of a single point draw press employing the present invention;

FIG. 2 is a front `elevational view, with parts cut away, of the press shown in FIG. l.

IFIG. 3 is a view, partly schematic, of the operating linkage for the blank holder slide of the draw press shown in FIG. l.

FIG. 4 is a perspective view, partly schematic, showing the die and blank 'holder slides of the press of FIG. l, their operating linkages, and their relationship to the press frame;

FIG. 5 is a fragmentary, detailed view `of a portion of the blank holder operating linkage; and

FIG. 6 is a `diagram showing the motions of the die and blank holder slides for one revolution of the crank shaft.

Referring to the drawings, the press of the preferred embodiment comprises a frame 10 having spaced upright side plates or members 11, 12, a crown 13 at the 3,052,200 Patented Sept. 4, 1962 icc upper ends of the side plates, and a stationary die plate 14 extending between the side plates at their lower ends. A blank holder slide 15 for holding the blank during the drawing loperation is positioned between the two plates 11, 12, and is vertically reciprocable on way plates 16 bolted to the side plates 11, 12. Two way plates 16 are mounted on each side plate and each corner of the blank holder slide 15 is formed with a way 17 which cooperates With the adjacent way plate 16 to guide the movement of the blank holder slide. A ldie slide y18 for supporting and reciprocating the drawing die is disposed within the blank holder slide 15 and is reciprocable with respect thereto `and with respect to the frame. The inner sides of the blank holder slide 15 are formed with Ways 20 for guiding the movement of the die slide.

The blank holder and die slides 15, 18 are reciprocated by an operating mechanism positioned within the crown 13 of the press and connected to the slides by linkages to be described in detail. The operating mechanism includes a crank shaft 19, rotatably supported in the crown of the press and driven from a motor 2t) mounted on the .press crown. The -rnotor 20 is connected to the crankshaft through a belt drive 21, and a gear train G driven by the belt drive and including =a pinion gear 22 which meshes with a bull `gear 22a` `fixed to one end of the crankshaft 19. The crankshaft 19 extends between the side plates 11, 12, and is formed with an eccentric 23 intermediate its ends and positioned approximately in the center of the press. An eccentric strap 24- ha-ving an upwardly extending arm 25 and a downwardly extending arm 26 is positioned on the eccentric 23. The anni 2S of the eccentric strap is Iconnected to the frame of the press by a link 27 and the arm 26 is connected to the die slide 18 by a link 28. The link 28 is pivotally connected at its upper end to the arm 26 by -a pin 29 and at its lower end t-o the die slide 18 by a conventional connection 30 best shown in FIGS. 1 and 2. Since the connection 30 is conventional, it will not be described herein; suce it to say that the connection is of the type which permits adjustment of the position of die slide 18 relative to the link 28 as well as permitting the necessary pivotal movement between the link and the die slide. It will be noted that the larm 26 and the link 28 form a toggle linkage which actuates the die slide 18 upon rotation of the eccentric 23.

The motion of the eccentric strap 24 to straighten and break the toggle linkage formed by the arm 26 and the link 2S is constrained by the link 27 which causes the point of the pivotal connection of the link 27 to the eccentric strap y24 to move along an arc about the connection of the link 27 to the frame. The link 27 is pivoted at its opposite ends to the frame and eccentric strap by pivot pins 31, 32 respectively. It will be noted that the pivotal connection of the link 27 to the frame is below a horizontal plane though the axis of the crankshaft 19 and the pivotal connection between the link 27 and the arm 25 is on the same side of the center line of the press and above the horizontal plane through the axis `of lthe crankshaft. The described llinkage for operating the die slide causes the knee of the linkage to take an elliptical path With the excursion `of the knee on one side of its straight line position being of greater extent that its excursion on the other side of the straight line position. The resultant die slide motion is shown by curve A in FIG. 6. It will be noted that a long draw stroke occurs with a rapid return motion for each revolution of the crankshaft.

The lblank holder slide 15 is also operated by the eccentric 23 through an actuating mechanism which includes a rocker member 33 rotatably supported on a shaft 34 supported in the crown y13 parallel to the crankshaft 19. The rocker member 33 includes an arm 35 extending upwardly therefrom and pivotally connected to the eccentric strap 24 by a link 36. The link 36 is pivoted to the eccentric strap by a pivotal connection 37 and to the arm 3S by a pivotal connection 38 which is best shown in FIG. 3. The shaft 34, which supports the rocker member 33, and the pivotal connection 38 are located in the same quadrant of those quadrants defined by a vertical and a horizontal plane through the axis of the crankshaft 19 as the pivotal connection of the link 27 to the frame. The pivotal connection 37 between the eccentric strap 24 and the link 36 describes an elliptical path, as shown in FIG. 3, which has its axis tilted slightly with respect to the horizontal and which extends into the adjacent quadrant proceeding in a clockwise direction.

The rocker member 33 extends between the side plates 11, 12 and has arms 39 extending radially outwardly therefrom adjacent to the plates 11, 12 respectively. The arms 39 are generally perpendicular to the arm 35 and may be said to form therewith a bell crank lever.

The outer ends of the arms 39 are each connected to one of a pair of slide members 40, 41 by a respective link 42, the slide members being supported for vertical movement by the side plates 11, 12 respectively. The slide member 40 is shown in detail in FIG. 5 and is reciprocable in a slide way 43 on the side plate 11 formed by a pair of parallel plates 44 engaging the opposite vertical edges of the slide member 40 and having caps 4-5 bolted to the outer faces thereof. The caps 45 overlie the slide member` 40 to prevent movement thereof in a direction away from the side plate 11. The slide member 40` is a T- shaped member, having a cross portion 46 at its upper end with the corresponding link 42 being connected to the center of the cross section 46. The cross portion 46 extends over the ends of plates 44 and directs the downward movement of the slide member 40. The slide member 41 is shaped in a manner similar to slide member 40 and is similarly supported on the side plate 12 by a slide way 43.

Reciprocation of the slide members 40; 41 upon rotation of the eccentric 23 actuates toggle linkages 47 for reciprocating the blank holder slide 1S. In the preferred and illustrated embodiment four toggle linkages 47 are provided with the toggle linkages lying in planes parallel to the side plates and Ibeing `connected to the front and rear sides of the rectangular blank holder slide adjacent the four corners thereof. The front and rear toggle linkages on each side of the press are connected to the slide member supported Iby the adjacent side plate.

The toggle linkages 47 for operating the blank holder slide are similar and therefore only the linkages operated by the slide member 4i) will be described in det-ail and similar reference numerals for corresponding parts will be applied to the linkages operated by the slide member 41. The front and rear toggle linkages operated by the die slide 40 each comprise a link 48 pivotally connected at its lower end to the blank holder slide 18 by an adjustable connection 49 and at its upper end by a pivot pin 51 to a rocker lever 50. The rocker lever 50 is pivoted intermediate its ends on a pin 52 supported by the press frame. When the blank holder slide 18` is in its lowermost position, the rocker lever 50` is substantially vertical with its lower end being the one connected to the link 48. The other end of the lever Si) is pivoted to a link 53 which, in turn, is pivotally connected to the adjacent end of the cross portion 46 of the T-shaped slide member 40 by a pivot pin 54. It can 'be seen that the rocker lever 50 and the link 48 of each of the linkages form a toggle linkage which will be moved to a straight line position when the slide member 4()` is moved to a position where the cross portion 46 thereof and the links 53 are disposed in horizontal alignment and is broken by movement of the slide member 40 from this position. In the prefer-red and illustrated embodiment, the slide member 4t) is moved downwardly to break the toggle linkages connected there to raise the blank holder slide when the linkages are broken and the knees thereof break outwardly of the press.

From the above description it can be seen that the operating mechanism for the blank holder slide 18 is of eX- tremely simple and compact construction and that if desired, 4the slide member 40, a member forming the slide way 43, and the toggle linkages connected to the slide member 40 may be pre-assembled and installed as a unit in the press. Furthermore, it can be seen that the mechanism for operating the blank holder slide is extremely compact and does not require a large spacing between the side plates of the press to accommodate the mechanism for operating the blank holder slide.

It can now be seen that the objects heretofore enumerated and others have been accomplished; and while the preferred embodiment of the present invention has been described in considerable detail, it will be apparent that the invention is not limited to the construction shown and it is -my intention to cover hereby all adaptations, modications and changes which come within the practice of those skilled in the art to which the invention relates and the scope of the appended claims.

Having thus described our invention, we claim:

1. In a power press having a frame including spaced upright side members, a reciprocable first slide disposed between said upright members, and a second slide within and reciprocable relative to said rst slide, a horizontal crank shaft extending transversely of said side plates at their upper ends, an eccentric crank on said crankshaft, an eccentric strap on said crank and having angularly related arms, a link pivotally connected to one of said arms and to said second slide and forming with said one arm a toggle linkage for operating the second slide, said link and one arm lying along a vertical line through the axis of said crank shaft when said die slide is in its lowermost position, the other arm of said strap extending into an upper quadrant of the quadrants defined by the vertical plane and the horizontal plane containing said axis, a link pivotally connected to the frame at a point in the lower quadrant adjacent said upper quadrant and to said other arm at a point in said upper quadrant, a rocker member in said lower quadrant and rockable about an axis parallel to said crankshaft, said rocker member having a pair of generally horizontal arms extending radially outwardly therefrom and an arm portion extending radially upwardly therefrom, a link having one end pivoted to said arm portion at a point in said lower `quadrant and to said strap, first and second slide members, means supporting a different one of said slide members for vertical movement on the inner side of each of said upright members, a respective link pivotally connected to each of said slide members and to a respective one of said horizontal arms, a rocker lever positioned on each of the opposite sides of each of said slide members and rockable about horizontal axes perpendicular to said upright member, a respective link pivotally connected to one end of each of said rocker levers and to said first slide, and respective links pivotally connected to the `other ends of said rocker levers and to the adjacent one of said slide members.

2. In a power press having a yframe including spaced upright side members and a reciproca-ble first slide disposed between the side members, a second slide reciprocable relative to said rst slide and said frame, a linkage adjacent the inner side of each of said side members and operatively Aconnected to said first slide for reciprocating the latter upon actuation of the linkages, a slide member reciprocably supported by each upright member, means connecting said linkages to the adjacent slide members for actuation thereby upon recip-rocation of the slide member, means lfor reciprocating said slide members comprising a single horizontally extending oscillatable member supported by `said frame Ifor oscillatory movement and extending between said slide members, a drive shaft rotatably supported by lsaid frame and extending parallel to said oscillatafble member, said oscillatable member being supported 'by said frame for rocking movement about an axis parallel to said drive shaft, an eccentric corinected to said drive shaft ifor rotation therewith, an eccentric strap cooperating with said eccentric and constrained to move in a predetermined manner upon rotation of said eccentric, means operatively connecting said eccentric strap to said oscillatable member to oscillate the latter upon rotation of said eccentric7 and linkage means operatively connecting said strap to said second slide to recip- -rocate the latter upon rotation of said eccentric.

3. In a power pre-ss having a frame including spaced upright side members, a reciprocable first `slide disposed between said upright members, and a second slide reciprocable relative to said first slide and said frame, a horizontal `drive shaft extending transversely between said side members, an eccentric crank on said `drive shaft, an eccentric strap `on said crank and having angularly related arms, a link pivotally connected to one of said arms and to said second slide and forming with said one of said arms a toggle linkage for reciprocating the `second slide upon rotation of said drive shaft, said link and `said one of said arms lying along a vertical line through the axis of said drive shaft when said second slide is in its lower most position, the other arm of said `strap extending into an upper quadrant of the quadrants defined by vertical and horizontal planes containing said axis, a 4link pivotally connected to the frame at a point in the lower quadrant adjacent said upper quadrant, a rocket member in said lower quadrant and rockable about an axis parallel to said drive shaft, said rocker member having a pair of generally horizontally extending arms extending radially outwardly therefrom and an arm portion extending radially upwardly therefrom, a link having one end pivoted to said arm portion at a point in said lower quadrant and the other end pivoted to said strap, first and second operating linkages respectively adjacent a respective one of said upright members, means operatively connecting said operating linka-ges to said rst slide to reciprocate the latter upon actuation of the linkages, and means connecting said linkages to a respective `one of said arms of said rocker member whereby said operating linkages are actuated to reciprocate said tirst slide upon the rocking of said rocker member.

References Cited in the tile of this patent UNITED STATES PATENTS 564,990 Good Aug. 4, 1896 2,364,661 Rode Dec. l2, 1944 2,491,317 Klocke Dec. 13, 1949 2,503,037 Georgeff Apr. 4, 1950 2,522,746 Byerlein Sept. 19, 1950 2,548,296 Femons Api'. 10, 1951 2,579,078 Johansen Dec. 18, 1951 2,644,417 Georgeff July 7, 1953 2,738,748 Hecht Mar. 20, 1956 2,767,674 Ott Oct. 23, 1956 

